Tuesday, September 08, 2009

A Quick Survey of New Nuclear Technologies

After they solve the engineering problems, new power sources are faced with government bureaucracy -- perhaps the most insurmountable problem of all. Today we'll look at emerging nuclear power sources. Later we'll consider how to escape the chokehold of bureaucratic obstructionists. The article below is excerpted from GreentechMedia.

Small Fission Reactors

Instead of building reactors capable of producing 1 to over 3 gigawatts of power, these reactors individually can generate 25 to 300 megawatts of heat and/or electricity. They work in the same manner as conventional reactors and coal plants: Nuclear fuel creates steam, which turns a turbine.

The individual reactors can be deployed to provide power to isolated communities or off-grid industrial sites like mines that are currently served by diesel generators. Alternatively, they can be chain-ganged together to provide the close to the same amount of power of a large facility.

The electricity from these small plants will cost about 6 to 9 cents a kilowatt hour over a lifetime to generate, or about the same as a conventional plant. (Nuclear plants in the U.S. can provide power for 7 to 8 cents a kilowatt hour; the price in the U.S. is around 6 to 8 cents with loan guarantees and 8 to 10 cents a kilowatt hour without.) The advantage comes in safety and more rapid construction.

• Sandia National Labs.

...The Sandia reactor will be capable of putting out 100 to 300 megawatts of thermal power (large for mini-nukes) and can be sealed for several decades without refueling (curbing nuclear waste and proliferation.) The reactor core itself will sit inside an envelope of liquid sodium to cool it, which eliminates the need for pumps, pipes and other equipment that can fail. Exporting it to emerging nations is one of the goals.

Ideally, a manufacturer could make 50 of them a year at $250 million each, which translates to electricity at 5 cents a kilowatt hour. Each individual reactor might take two years to build.

• NuScale Power. Funded by venture firm CMEA, NuScale essentially is developing a smaller, similar reactor: It will generate 45 megawatts of electricity and feature a passive cooling system that relies on water. By connecting 12 or 24 into an array, NuScale hopes to build power plants that will produce power for 6 to 9 cents a kilowatt hour. Although that's roughly the same price as regular nuclear plants, NuScale's advantage is that construction time could be considerably less. That ominous, complex cement dome won't be required.

Unlike Sandia's reactor, NuScale's needs to be refueled every few years.

• Babcock & Wilcox

The company's mPower light water reactor will generate 125 megawatts of power. The underground reactor would be refueled every five years and last 60 years. The company will likely submit its designs to the NRC in 2011 or 2012, putting the expected date for an operation plant toward 2020. The Tennessee Valley Authority has already begun the long evaluation process.

• TerraPower.

Disposal and power all in one. TerraPower wants to create reactors that will run on depleted uranium from nuclear waste sites or, possibly, thorium. Besides reducing nuclear waste stockpiles, depleted uranium reactors could conceivably extend uranium supplies for hundreds of years.

• Hyperion Power Generation. The mini-mini. Hyperion's reactor, measuring 1.5 meters in diameter and about the size of a hot tub, will generate 70 megawatts of heat or 25 megawatts of energy. Hyperion buries the reactor in a cement chamber, where it only needs to be refueled every five years. The company, which came out of Los Alamos National Lab, hopes to start delivering reactors in 2013 for a price of $25 million to $30 million. Altira Group is the main investor and more funds are being sought.

Hyperion's initial target will be military bases, tar-sands mines (where it could be used to clean gummy oils) and other isolated, off-grid communities with large power needs. CEO John Deal is one of the more visible executives in this market.

Thorium Reactors

Far more common than uranium, thorium can be mixed with a small amount of uranium, bombarded with neutrons and turned into a U-233 to produce the necessary heat. Thorium reactors do not produce weapons-grade plutonium either. While some early reactors employed thorium, though, uranium swept the industry because the reaction generates more energy. Now, it may make a comeback.

• Thorium Power. D.C.-based Thorium Power was founded in 1992 to capitalize on the research of Alvin Radkowsky, who worked with Edward Teller and Hyman Rickover. The company began to collaborate with Russia's Kurchatov Institute two years later. In 2007, it inked an alliance with Red Star, a government owned nuclear plant designer.

• Lawrence Livermore National Labs. The National Ignition Facility (NIF) at the lab has devised a stadium-sized laser with 192 extremely-high powered beams. The beams can be focused onto a spot about a half a millimeter in diameter in a target chamber. If the energy can be delivered onto a fuel pellet made up hydrogen isotopes, it can conceivably cause the atoms to fuse into a form of helium, and thereby deliver more power than the lasers consume. The goal is to demo the laser in 2010 or 2011.

• MIT. Among other nuclear projects, MIT last year showed how it can exploit radio waves to propel the hot hydrogen plasma (a precursor to fusion) inside a reactor without hitting the walls or causing turbulence, which can interfere with fusion reactions.

• Tri-Alpha Energy. Founded in 1998 from research conducted at UC Irvine, Tri-Alpha creates a fusion reaction with hydrogen and boron. It raised $40 million in 2007 from, among others, Venrock.

• General Fusion. Canada's General Fusion uses a technique called Magnetized Target Fusion (MTF) model. In this scenario, an electric current is generated in a conductive cavity containing lithium and a plasma. The electric current produces a magnetic field and the cavity is collapsed, which results in a massive temperature spike.

The lithium breaks down into helium and tritium. Tritium, an unstable form of hydrogen, is separated and then mixed with deuterium, another form of hydrogen. The two fuse and make helium, a reaction that releases energy that can be harvested. (They also have a picture of a cool dinosaur on their website.)

Fission Fusion Hybrid

A supplemental form of power with Lawrence Livermore's LIFE reactor. In this scenario, the fusion core is wrapped in blankets consisting of uranium, depleted uranium, thorium, plutonium or other nuclear material. Neutrons released during the fusion process would pass through a series of plates to a layer of metallic pebbles, releasing more neutrons which turn would hit the f blanket, causing fission reactions. Ideally, the system would consume nuclear waste and generate fission power without generating chain reactions. (More on this in a subsequent article.)

Molecular Manipulation

Technically, not fission or fusion at all, but a form of exploiting the properties of various materials to release energy.

The CEA, France's Nuclear Commission, has an ambient thermoelectric generator that can release 4 milliwatts per square centimeter for every (Celsius) degree difference via the Seebeck Effect (coined by Estonian physicist Thomas Seebeck). In the Seebeck Effect, electric current can be generated by the energy differences between two materials in close proximity. The Seebeck Effect typically works because of extreme temperature variations – i.e., a hot pipe in a cold room. Potentially, new materials could create Seebeck power at normal temperatures.

In the same vein, deep-space spacecraft now employ nuclear batteries. In these, plutonium is wrapped in a thermoelectric material (like bismuth telluride) that converts heat into electricity. Nuclear batteries are far more efficient than lithium-ion batteries but are probably impractical for widespread commercial use, according to IBM's Winfried Wilcke.

Blacklight Power says it has discovered a new form of hydrogen called a Hydrino. When ordinary hydrogen is mixed with a chemical catalyst at a relatively cool 50 degrees Celsius, hydrogen molecules turn into hydrinos, according to Blacklight. The hydrogen-to-hydrino reaction releases 200 times more energy than the amount of energy that gets released when hydrogen is burned.

"The hydrogen releases an extremely large amount of energy. There is unequivocally energy being produced," said CEO Randell Mills.

Cold Fusion

Michael McKubre from SRI International continues to determine whether one could dunk palladium into water infused with the hydrogen isotope deuterium and apply an electric current. Voilà, you'd have an electric battery. The cold fusion concept has been heaped with scorn since 1989 when two University of Utah professors published papers on it. Critics noted that other institutions weren't finding the same results. _GreentechMedia

The Bussard IEC fusion approach is another approach to small fusion that has shown some promise.

Breakthroughs do not come to order. They take time, and have to be proven out.

Unfortunately, technical feasibility and functionality is not enough in this day and age. What do do about government bureaucratic obstructionism will be the topic of a future posting.